display custom unit with slash

contracts/templates/contracts/view_contract.html

@@ -105,7 +105,7 @@
                         {% if contract.cost_unit == contract.CostUnits.TOTAL %}
                             celkem
                         {% elif contract.cost_unit == contract.CostUnits.OTHER %}
-                            {{ contract.cost_unit_other }}
+                            / {{ contract.cost_unit_other }}
                         {% else %}
                             / {{ contract.get_cost_unit_display.lower }}
                         {% endif %}